stevens



w. N. STEVENS.

CONTINUOUSLY OPERATING DRH-1R.

APPLICATION FILED APR. I4. |917.

1,3035982. Patented May 20, 1919.

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Patented May`20, 1919.

2 SHEETS-SHEET 2.

ATTORNEYS,

ITE ST A11-13s A A. TENT OFFICE.

WILLIAM N. STEVENS, oF BROOKLYN, NEW YORK, AssIGNoR To sTEvENs-AYLswoRTII COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK CONTINUOUSLY-OPERATING- DRIER.

Specification of Letters Patent.

Patented May 20, 1919.

Application lerl April 14, 1917. Serial No. 162,034.

To all whom t may concern.'

Be it known that I, WILLIAM N. STEVENS, a citizen of the United States, and a resident of Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Continuously-Operating Driers, of which the following is a specication; i

My invention relates to driers and more particularly to that class of driers in which the wet material or charge to be dried` is passed through a vacuum chamber and the chamber subjected to a heating medium in order to effectively free the charge or wet material from all moisture.

The obj ect of my invention is the production of 4a drier of the character above described whichshall be effective and positive in its operation and which shall be of simple construction and of low cost to manufacture.

A further Object ofv my invention is the production of a drier having the' above characteristics and which shall be continuous in operation.

In the usual form of driers now in use a chargeof the material to be `dried is placed in the machine which is sealed up and a vacuum established therein. The material is then stirred or shaken up until it is dry after which the vacuum is destroyed and the machine discharged to make room for a new charge. With these machines there is no meansr of ascertaining when. the materials have given up all their moisture and as a consequence the charges are permitted to remain in the driers much'longer than is necessary. Furthermore there is much time lost in discharging, recharging, sealingy up the machineY and restablishing the vacuum.

By means of Ymy invention I haveV produced a drier that operates continuously so that the ,material comprising, a solution or a liquid with materials in suspension may be fed intoythe drier all day or any required number of days without destroying the vacuum and duringthis period the machine Operates continuously at itsmaXimum capac'ity'. At any given period as, once a day or once in several days, the machine may be stopped and the dried material removed.

The invention consists in the improved construction of drier Vhereinafter more particularlydescribed and then specified in the claims.

dIn the drawings:

Figure 1 is a horizontal central section (partly in elevation) taken through my improved drier.

Fig. 2 is an end elevation of the same.

Referring more particularly to both figures of the drawings in which like gures of reference denote corresponding parts in both the views,-

1 2 indicate cylinders preferably having a single or common front wall 3 and a single or common rear wall 4 by which they are held together. Each of said cylinders is provided with a screw conveyer indicated at 5 and 6 respectively extending lengthwise through the cylinders. The ends of the shafts of said screw conveyers extend through the walls 3 and 4 and are journaled in suitable bearings 7 and 8 respectively, which are held or fastened to the walls 3 and 4 in any desirable manner. To render the cylinders air-tight I have provided the shafts of the screw conveyers where they pass through the walls 3 and 4 with suitable standing-boxes as illustrated.

9 indicates a sprocket keyed to the forward end of the shaft of the screw conveyer 5 and 10 indicates a gear wheel carried by the rear end of said shaft. Said gear wheel 10 meshes with a gear wheel 11 of relatively large size which is carried by the rear end of the shaft of the screw conveyer 6. Obviously, the machine may be operated by connecting, by means of a chain or otherwise, the sprocket 9 with any suitable driving power in which case the screw conveyer 5 will rotate towardthe right and the screw conveyer 6 will rotate toward the left at a slower speed than that of the conveyer 5, on account of the relatively large size of the gear wheel 11 as compared with thegear wheel 10 with which it-meshes.

12 indicates the inlet pipe through which the charge to be dried is passed into the cylinder 1 and which connects with said cylinder near the forward end thereof. A hopper or reservoir 13 having a neck portion 14 and a suitable valve therein connects with said inlet pipe 12. The cylinders 1 and 2 near their rear ends are connected together by a pipe 15, and cylind'er 2 near its forward end is provided with an outlet pipe 17 connecting with a storage tank 18. The y storage tank has an opening in the lower wall thereof and is provided with a stopper Vor other suitable closure 19 for said opening.

2O indicates a tapped hole in the rear wall 4 and lead'ing into cylinder 1. Said tapped holev is adapted for the connection of a vacuum pump to the cylinder so that when the valve 14 is closed. and the opening in the storage tank 18 is closed by the stopper 19 a vacuum can be expeditiously and effectively established in both the cylinders by means of the vacuum pump.

21 indicates a jacket which preferably completely surrounds i both cylinders and which is provided with a conventional form of inlet valve 22 andv outlet valve 23 for the vadmission and emission respectively of a heating medium such as hot liquids or steam. 24 indicates a suitable framework for supporting the drier and it is provided with a platform 25 for supporting the storage tank 18. The framework is preferably constructed' in such a manner that the cylinders are at Van angle from the horizontal with the rear portion of the cylinders higher than the front portionthereof as illustrated.

The operation of the drier is'as follows:

The valve 14 is closed and the opening in the bottom of the tank 18 is plugged with the stopper 19 after which a vacuum is,es tablished within the cylinders by means 0f the vacuum pump as has heretofore been explained. The machine is then set in operation so as to rotate the screw conveyers 5 and 6 in opposite directions and the hopper 13 is filled with the material to be dried. is cracked or slightly opened to permit the charge to run slowly into cylinder 1. The charge, which is usually in liquid form, forms a shallow pool at the forward end of the cylinder and is prevented from running directly to the rea-r end thereof due to the fact that the cylinder is inclined to the horizontal as has been described. The charge is then forced through the cylinder 1 by the blades of the screw conveyer 5 which turn the charge over and over forcing it against all parts of the hot surface of the cylinder and the charge thus slowly loses a great amount of its moisture due not only to the heating of the cylinder but also to the vacuum established therein., When the charge has reached the end of cylinder 1 it becomes more solid in' form and falls through pipe 15 into cylinder 2. The charge, now partially dried, is subjected to the same drying process in cylinder 2 that it 'received in cylinder 1, but it is forced Vthrough the cylinder by the blades of the screw conveyer 6, now that it has reached a semi-solid state, more slowly than it was forced through cylinder 1 so as to insure positively that it will be relieved of all its moisture when it reaches the forward end of the cylinder and so that it will fall into the After filling the hopper, valve 14V storage tank 18 through .pipe 17 in practically solid form.' yObviously the hopper 13 per, so that the machine in reality is a continuously operating one. The vacuum is destroyed only when the hopper is empty and the valve 14 is open or when it is desired to discharge the drier by withdrawing the stopper 19 and removing the dried material. Y v

What I claim as my inventionfis Y l l. In a drier, a cylinder inclined to the horizontal, an inlet adjacent the lower end of the cylinder for delivering a liquid mate-l rial to be dried thereto and means for forcing the material to be dried through the cylinder and against the action Yof gravity after it has partially lost its moisture.

2. In a drier, a vacuum cylinder inclined to the horizontal, an inlet receptaclefor said vacuum cylinder adapted to receive the material to be dnied and provided with a valve for permitting said material to ow continuously 'by the action of gravity directly to the lower end of said vacuum cylinder with1 out destroying the vacuum therein, said vacuum cylinder being adapted to retain the material t0 be dried in the lower end thereof' until said material has partially lost its moisture.

3. In a drier, a vacuum cylinder, a screw conveyer adapted to force the material to be -dried upwardly thro-ugh said cylinder against Ithe action of gravity and means for continuously feeding the material to said cylinder without destroyingA the vacuum therein.

4. In a drier, a vacuum cylinder inclined toward the horizontal, an inlet adapted to deliver the material to be dried adjacent the lower end of the cylinder, a jacket surrounding said cylinder and containing la li-uid for heating said vacuum cylinder and mean's for forcing the material to be dried through said vacuuml cylinder.

5. In a drier, a vacuum cylinder, a j acket' 6. Ina drier, a plurality of vacuum cylin Y de rs inclined to the horizontal and connected with each other, a screw/-conveyer for each cylinder adapted to force thematerial to be dried through said cylinders and around the 4inner surface thereof, means for rotating the screw conveyers at different. speeds, a jacket surrounding said cylinders and containinga fluid for heating the same, a storage tank connected with said cylinders for receiving the dried material and an inlet pipe adjacent the lower end of the first cylinder and 5 having means permitting the continuous feeding of the material to be dried to said cylinders without destroying the vacuum therein.

7. In a drier, a cylinder, means permit/ting 10 the material t0 be dried to flow continuously into said cylinder by gravity and without destroying the vacuum therein and a sealed storage tank connected with said cylinder for receiving the dried material.

Signed at New York, in the county of 15 New York and State of New York, this 13th day of April, A. D. 1917. a

WLLIAM N. STEVENS.

Witnesses:

W. R. WARNER, F. B. ToWNsEND.

copie: of this patent may be obtained for ive cents each, by addressing the Commissioner of Patents, Washington, D. C. 

